Commercial Wiring........

[Mustang]

Hello everyone,

I am currently learning about commercial wiring. In my local town hall they have a three phase supply. The sockets in the hall are surface mounted with the mini trunking running between them. The wiring comprises of 2 x phase, 2 x neutral and 2 x earth cabling. Just wondered why there is 2 of each cable? Also what type and size would these cables be?
I know these are probably simple questions to most but I'm still learning!! Thanks for any help!

 

[danzor]

ring main? Guessing its wired in singles and its prob 2.5/4.0mm

 

[Hawk81]

the reason for 2 of each cable is because 1 set ie live neutral and earth come from the supply and then go from that socket to the next and so on. possibly the last socket loops back to the supply. ring main. cable is more than likely 2.5mm or 4mm.